I got a reply from Josh, who wants to set up a studbook for Pelusios and Pelomedusa. I quote it in full here:

Marnix,

Glad to hear from you. I am still setting up the database with little interest from the TSA as Pelusios & Pelomedusa are category 4 (very little concern). I do feel that the better now than latter approach will pay off. Dan would want to contact Bill Zeigler from TSA as they are looking for a volunteer to head that taxon management group (studbook).

The link below will take them to the TSA coordinator page and from there they can find more information with the plans in place here in the states.

Marnix, You are awesome. Thank you for the directioning. I need to find some sponsers to become a tsa member but i am sure i can find them. I love to find more people that have the same love for turtles as i do.

would your friend josh be willing to identify my African side necks? I know there are like 20 sub species and id like to know mine. I saw his post on fauna classifieds but haven't been able to get a response, fauna is a little more confusing of a forum for me. I will send him pics if need be. I just got a male for my female and i think there is a difference between the two now. Any help would be awesome. Thanks